Wow!• A potential alien signal• 1977

Big Ear• Ohio State University• Radio Telescope, transit instrument• (Design similar to Nancay Radio Telescope)

Location on Sky

• Sweeps across any given part of the sky in 72 sec

21 cm Hydrogen line

What does the signal mean?

Many follow-ups, including:

• Oak Ridge Observatory, 1987, 1989

• 12m NRAO West Bank, 1995

• VLA, 1995, 1996

• Mt. Pleasant Radio Obsy, 1999

Conclusion

• No clue! • Could be

– Alien– Military – Noise (low chance

but not impossible)

• Probably not…– Accidental human

(21cm banned)

– Natural astronomical (narrow band)

• 2012 Aricebo beamed 10,000 Tweets to that direction of sky